Thinner is better?

[Dominic]

TMR you could run a 0W-20 yearround and be fine, no worries.

As far as viscosity goes it's my understanding that if you go TOO thick then you impede flow, and if you go TOO thin then you fail to lubricate. The question is, on a 70F normal day cruising at a normal 70mph... when you go to pass the 18 wheeler and downshift putting 100% load on the engine... is that 5W20 going to be protecting it?

I tend to go for what's on the oil cap. I never know when I might cross death valley, and I don't wanna change my oil first to do it.

 

[FZ1]

Right. The synthetic flows quicker than the dino at the same weight.

 

[Gary Allan]

Originally Posted By: Steve S
Originally Posted By: 98LSC32V
Originally Posted By: double vanos
I think Bill in Utah has it nailed in his signature - Use the BEST oil for your car - follow your manual for TYPE and OCI.

Just look at his UOA's.....the prosecution rests.

Cheers all!!


My manual says use 5w30 but the engine is back speced for 5w-20 so i'm using 0w-20, should I switch back?
There we go ,,it is your car and you can use what ever oil you want.


So, engineers can rethink themselves? Weren't they smart enough on it the first time through?

I reality most engines can do just fine on 20 weight oils. They've been doing it for a very long time in the 70's, 80's, and through the 90's. The shear prone oils of those times degraded to 20 weights ..and all of the numb consumers were happy as clams "using the specified oil" (just obey the law!! - grounding the football for yardage is a penalty - grounding it for time ..is not). The ONLY thing that changed is that someone bothered to bring a 5w-20 to market and assure it's availability.

Always ask "why".

 

[Oilgal]

Originally Posted By: JAG
LOL. Oilgal, you're welcome. That second link above was posted in the Interesting Articles forum. If you haven't already, check out most of the threads there. It's loaded with high quality information. Tribology is as "hard" as any of the physical science subjects because it's a combination of many of them. If you want to read some papers that are not available online for free, PM me and I can email them to you.

Thanks for the support farrarfan1.



Thank you, so very much, for caring enough to speak up.

It is going to take me, some considerable time, to even get to the stupid question point regarding this. I am now trying to sidestep the math, that sadly I cannot grasp at all, to glean at least some contextual understanding of hydrostatic and hydrodynamic lubrication, as it relates to lubricant viscosity, flow and fluid pressure, ... I think.

Nearly everything, I think I understand about "these things", is all dead wrong. More and more I realize, that my dear old daddy himself, taught me a lot of automotive myths, and I am very lucky that you guys even tolerate me at all here. I don't know why I am so interested in these things, mom would not approve that's for certain, and now I suspect it's a "daddy thing". OMG! When will it all end?

 

[Steve S]

Originally Posted By: FZ1
Right. The synthetic flows quicker than the dino at the same weight.
How so?

 

[FZ1]

Lower pour point.

 

[Steve S]

What will be the difference ?

 

[Steve S]

Originally Posted By: Gary Allan
Originally Posted By: Steve S
Originally Posted By: 98LSC32V
Originally Posted By: double vanos
I think Bill in Utah has it nailed in his signature - Use the BEST oil for your car - follow your manual for TYPE and OCI.

Just look at his UOA's.....the prosecution rests.

Cheers all!!


My manual says use 5w30 but the engine is back speced for 5w-20 so i'm using 0w-20, should I switch back?
There we go ,,it is your car and you can use what ever oil you want.


So, engineers can rethink themselves? Weren't they smart enough on it the first time through?

I reality most engines can do just fine on 20 weight oils. They've been doing it for a very long time in the 70's, 80's, and through the 90's. The shear prone oils of those times degraded to 20 weights ..and all of the numb consumers were happy as clams "using the specified oil" (just obey the law!! - grounding the football for yardage is a penalty - grounding it for time ..is not). The ONLY thing that changed is that someone bothered to bring a 5w-20 to market and assure it's availability.

Always ask "why".
Gary the last time I inferred why ,you said I was no fun!!!!

 

[1sttruck]

We see or hear of evidence of unacceptable wear around here; flat tappet cams, flat tappet cams with high spring loads, sludging, newer VW engines seem picky about oil, peple running light oils in diesels.

I don't know if it's changed much but at one time a turbo on a gas engine typically meant shorter engine life and/or more frequent repairs. Better grade of oil would help, which is often seen in 'super cars' (like the one below :^). As a nexample Ford recommends Motorcraft 5W50 for it's GT.

http://www.mapperguru.com/Supercar.html

 

[dcoyne78]

Originally Posted By: Steve S
What will be the difference ?


It is simply a matter of looking at the specs of a dino vs synthetic oil for say a Pennzoil 5w30.
Viscosity______ 40 C 100C MRV@-35C
Pennz Plat 5w30 57.5 10.3 14800
Pennz Conv 5w30 63.9 10.5 25100

So the difference is that when the engine is cold on a 0 C winter morning the synthetic will be less viscous (thinner) than the conventional oil so it will flow better and protect the engine more on cold startup. Once the engine is at operating temperature there will be little difference.

 

[AEHaas]

"Ford recommends Motorcraft 5W50 for it's GT"

Jason from Heffner Performance:
http://web2.caranddriver.com/specialtyfi...i-gallardo.html
lives and works just down the road from here and comes to all our Ferrari events with a number of cars running in excess of 1,000 BHP on his dyno. We have had discussions regarding motor oil viscosity. He does recommend that most people use just a 40 grade oil in these engines unless they are racing the cars. Even then, the lower viscosities may be recommended. He does not feel that oil viscosity has ever ruined an engine. "It is always something else."

aehaas

 

[98LSC32V]

I read somewhere the valve train on the 5.4 DOHC supercharged Ford motors in the GT and Shelby GT500 was specially designed for the 50 weight oil.

 

[02zx9r]

Originally Posted By: AEHaas
" He does not feel that oil viscosity has ever ruined an engine. "It is always something else."

aehaas


I will agree with that statement!